[PATCH] RCU documentation fixes (January 2006 update)
Updates to in-tree RCU documentation based on comments over the past few
months.
Signed-off-by: "Paul E. McKenney" <paulmck@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/Documentation/RCU/checklist.txt b/Documentation/RCU/checklist.txt
index e118a7c..49e27cc 100644
--- a/Documentation/RCU/checklist.txt
+++ b/Documentation/RCU/checklist.txt
@@ -177,3 +177,9 @@
If you want to wait for some of these other things, you might
instead need to use synchronize_irq() or synchronize_sched().
+
+12. Any lock acquired by an RCU callback must be acquired elsewhere
+ with irq disabled, e.g., via spin_lock_irqsave(). Failing to
+ disable irq on a given acquisition of that lock will result in
+ deadlock as soon as the RCU callback happens to interrupt that
+ acquisition's critical section.